Flash Flood Prediction Program

-	Message 1's will continue valid for the District until 10pm this evening although a lull has developed over much of the District currently. Rain showers and weak thunderstorms continue over Boulder County at this time but rainfall rates are relatively light.
-	This lull is allowing for some late daytime heating that will likely generate another round of storms in 2-3hours. Although temperatures have cooled storms that develop will be efficient rain producers and even a moderate storm is still capable of producing rates of up to 0.5"/10mins or more.
-	Showers and thunderstorms will continue to be relatively fast moving from SW to NE at around 25mph which will help to reduce point rainfall amounts from a single storm. Training of thunderstorm cells will have the greatest potential to produce extended periods of heavy rainfall. After 9 or 10pm the threat for thunderstorms will diminish with additional rain showers possible overnight.

STORM RAINFALL POTENTIAL AND DURATION: Typical rain showers and weak to moderate thunderstorms will produce 0.1-0.5" in 10-30 minutes. Strong thunderstorms will have the potential to produce 0.5-1.5" in 10-30 minutes. Supplemental QPF is available at https://qpf.udfcd.org

WORST CASE SCENARIO: Training of thunderstorm cells or a very large slower moving thunderstorm may produce up to 2.5" of rain in 45-60 minutes.

County	Message	Valid Times	Prime Time
Adams County	1	Current TO 1000 PM	100 PM TO 900 PM
Douglas County	1	Current TO 1000 PM	100 PM TO 900 PM
Broomfield County	1	Current TO 1000 PM	100 PM TO 900 PM
Jefferson County	1	Current TO 1000 PM	100 PM TO 900 PM
Boulder County	1	Current TO 1000 PM	100 PM TO 900 PM
Denver County	1	Current TO 1000 PM	100 PM TO 900 PM
DIA	1	Current TO 1000 PM	100 PM TO 900 PM
Arapahoe County	1	Current TO 1000 PM	100 PM TO 900 PM
the City of Aurora	1	Current TO 1000 PM	100 PM TO 900 PM
Arvada	1	Current TO 1000 PM	100 PM TO 900 PM
Wheat Ridge	1	Current TO 1000 PM	100 PM TO 900 PM
Lakewood	1	Current TO 1000 PM	100 PM TO 900 PM

County-specific Quantitative Precipitation Outlook	Precipitation Time	30-Minute Rainfall and % Probability	Message Potential
Plains
Adams	Current TO 1000 PM FRI	0.1" (80%) to 0.5" (40%) to 1.5" (10%)	ISSUED
Arapahoe	Current TO 1000 PM FRI	0.1" (80%) to 0.5" (40%) to 1.5" (10%)	ISSUED
Boulder	Current TO 1000 PM FRI	0.1" (80%) to 0.5" (40%) to 1.5" (10%)	ISSUED
Broomfield	Current TO 1000 PM FRI	0.1" (80%) to 0.5" (40%) to 1.5" (10%)	ISSUED
Denver	Current TO 1000 PM FRI	0.1" (80%) to 0.5" (40%) to 1.5" (10%)	ISSUED
Douglas	Current TO 1000 PM FRI	0.1" (80%) to 0.5" (40%) to 1.5" (10%)	ISSUED
Jefferson	Current TO 1000 PM FRI	0.1" (80%) to 0.5" (40%) to 1.5" (10%)	ISSUED
Foothills above 6500ft
Boulder	Current TO 1000 PM FRI	0.1" (80%) to 0.5" (40%) to 1.5" (10%)	ISSUED
Douglas	Current TO 1000 PM FRI	0.1" (80%) to 0.5" (40%) to 1.5" (10%)	ISSUED
Jefferson	Current TO 1000 PM FRI	0.1" (80%) to 0.5" (40%) to 1.5" (10%)	ISSUED

MONITOR NATIONAL WEATHER SERVICE FOR SEVERE WEATHER STATEMENTS.